Overdrive Expert Needed

[Oldmics2]

Two questions

#1- Are point replacement parts available for inside of the solonoid ?

I cant believe that point sets were never available for such a simple repair but I can find nothing on them anywhere!

#2 - Here is my situation- The OD system (12volt) appears to have all of the componets working however it will not shift into the OD mode.

Now as crazy as this sounds - the rear differential ratio appears to be around 2.9.

Obviously the rear has been replaced. I believe that the governor will not spin fast enough due to the rear end ratio to activate the solonoid.

Could that be a possibility ?

I dont believe that an OD transmission would have been installed into a vehicle using a rear ratio numericaly lower than about 3.5 s- with most being in the 3:91 or 4:11 range.

I'm going to remove the governor and spin it with a drill to see if it will activate the solonoid.

Let me know what you guys think

Thanks

Oldmics 2 (ha,ha) - Wheres Kultulz ?

[40cpe]

The governor should still activate the relay, although at a higher speed than with normally geared overdrive drivetrain.

[miker98038]

40’s correct. Might be 35 or so, but should still go in. If the drill doesn’t work try running a jumper sw, out thru the hood and into the window if necessary. That should drop the relay in. If it work, and the drill motor checks out on the gov then it’ll be the wire or the connections.

K is occasionally active at yblocksforever.

[mcgarrett]

I'm not aware of any replacement points available for the solenoid. I had a similar problem with my OD. The problem was traced to a leaky solenoid plunger seal allowing tranny lube to get onto the points. The oil prevented the points from making contact. There are 2 sets of points inside...one set pulls the plunger into OD position and the second set holds the plunger in place. Remove the solenoid, take the case apart and see if there is oil on them.

[miker98038]

You can also call Mac at Van Pelt Sales. They list the solenoids for some models, but can possibly rebuild yours since you’ve got a core. The post about oil and points above is something I’ve heard before, even though I’ve never had it happen.

[rotorwrench]

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The contact in the old operating solenoids were made to stay in there for the life of the unit. Most Borg Warners use the same solenoid. Fifth Avenue Internet Garage was one of the first companies to offer new units. Most are the 1-inch type shaft extension but some are longer such as convertibles and station wagons due to the odd under slung solenoid set up they had.

As mentioned, oil leakage into the unit has to be stopped if so. Seals are available for the transmission interface. A person may be able to repair the old ones but they should take the cover off and see what they are up against before trying that.

A person with such a tall geared rear axle may not need an overdrive. The whole point was to get a heavy car up to rod speed with as low an engine rpm as possible. lower gears like the 3.9:1 Dana 44 in the Mercury cars needed an overdrive but they are a heavy car on their own plus being able to carry 6-passengers.